From 9757bb7dda5dfc3094f6f5e89d70653402ed629d Mon Sep 17 00:00:00 2001
From: Kaspar Schleiser <kaspar@schleiser.de>
Date: Fri, 10 Dec 2010 16:52:06 +0100
Subject: [PATCH] * many fixes. vtimer_hammer OK now.

---
 sys/vtimer.c | 37 +++++++++++++++++++++++--------------
 1 file changed, 23 insertions(+), 14 deletions(-)

diff --git a/sys/vtimer.c b/sys/vtimer.c
index 74e05adf8f..2ea9420eb8 100644
--- a/sys/vtimer.c
+++ b/sys/vtimer.c
@@ -13,6 +13,7 @@
 #include <debug.h>
 
 #define VTIMER_THRESHOLD 20U
+#define VTIMER_BACKOFF 10U
 
 #define SECONDS_PER_TICK (4096U)
 #define NANOSECONDS_PER_TICK (4096U * 1000000)
@@ -41,7 +42,7 @@ static int set_longterm(vtimer_t *timer) {
 }
 
 static int update_shortterm() {
-    if (hwtimer_id) {
+    if (hwtimer_id != -1) {
         if (hwtimer_next_absolute != shortterm_queue_root.next->priority) {
             hwtimer_remove(hwtimer_id);
         } else {
@@ -49,23 +50,24 @@ static int update_shortterm() {
         }
     }
 
-    uint32_t now = hwtimer_now();
+
     hwtimer_next_absolute = shortterm_queue_root.next->priority;
-    
-    while ((hwtimer_next_absolute + longterm_tick_start)-(hwtimer_now()+VTIMER_THRESHOLD) > NANOSECONDS_PER_TICK) {
-        hwtimer_next_absolute += VTIMER_THRESHOLD;
+
+    unsigned int next = hwtimer_next_absolute + longterm_tick_start;
+    unsigned int now = hwtimer_now();
+
+    if((next - VTIMER_THRESHOLD - now) > NANOSECONDS_PER_TICK ) {
+        next = now + VTIMER_BACKOFF;
     }
 
-    hwtimer_id = hwtimer_set_absolute(hwtimer_next_absolute + longterm_tick_start, vtimer_callback, NULL);
+    hwtimer_id = hwtimer_set_absolute(next, vtimer_callback, NULL);
 
     DEBUG("update_shortterm: Set hwtimer to %lu (now=%lu)\n", hwtimer_next_absolute + longterm_tick_start, hwtimer_now());
-    //printf("%lu (now=%lu)\n", hwtimer_next_absolute + longterm_tick_start, hwtimer_now());
-
     return 0;
 }
 
 void vtimer_tick(void *ptr) {
-    puts("vtimer_tick().");
+    DEBUG("vtimer_tick().");
     seconds += SECONDS_PER_TICK;
 
     longterm_tick_start = longterm_tick_timer.absolute.nanoseconds;
@@ -95,9 +97,12 @@ static int set_shortterm(vtimer_t *timer) {
 void vtimer_callback(void *ptr) {
     vtimer_t *timer;
     in_callback = true;
+    hwtimer_id = -1;
+
     timer = (vtimer_t *)queue_remove_head(&shortterm_queue_root);
 
     DEBUG("vtimer_callback(): Shooting %lu.\n", timer->absolute.nanoseconds);
+
     /* shoot timer */
     timer->action(timer->arg);
 
@@ -126,10 +131,6 @@ void normalize_to_tick(timex_t *time) {
 int vtimer_set(vtimer_t *timer, timex_t *offset) {
     DEBUG("vtimer_set(): New timer. Offset: %lu %lu\n", offset->seconds, offset->nanoseconds);
 
-
-//    timex_t vnow = vtimer_now();
-//    DEBUG("Now = %lu %lu\n", vnow.seconds, vnow.nanoseconds);
-
     timer->absolute = timex_add(vtimer_now(), *offset);
     normalize_to_tick(&(timer->absolute));
 
@@ -137,6 +138,12 @@ int vtimer_set(vtimer_t *timer, timex_t *offset) {
 
     int result = 0;
 
+    if (timer->absolute.seconds == 0) {
+        if (timer->absolute.nanoseconds > 10) {
+            timer->absolute.nanoseconds -= 10;
+        }
+    }
+
     int state = disableIRQ();
     if (timer->absolute.seconds != seconds ) {
         /* we're long-term */
@@ -167,6 +174,7 @@ timex_t vtimer_now() {
 
 int vtimer_init() {
     DEBUG("vtimer_init().\n");
+    int state = disableIRQ();
     seconds = 0;
 
     longterm_tick_timer.action = vtimer_tick;
@@ -180,13 +188,14 @@ int vtimer_init() {
     set_shortterm(&longterm_tick_timer);
     update_shortterm();
 
+    restoreIRQ(state);
     return 0;
 }
 
 int vtimer_usleep(uint32_t usecs) {
     vtimer_t t;
     timex_t offset = timex_set(0, usecs);
-    t.action = thread_wakeup;
+    t.action = (void*) thread_wakeup;
     t.arg = (void*) thread_getpid();
     vtimer_set(&t, &offset);
     thread_sleep();